In recent years, induction heating cookers have been widely used in ordinary homes, as cooking devices employing safe and clean heat sources which use no fire and exhaust no combustion gas (for example, European Patent Application Publication No. 1122983; Patent Literature 1). Further, such induction heating cookers have higher heating efficiencies than those of heating cooking utilizing combustion gas as heat sources. However, the heating efficiency varies depending on the relative permeability and the specific resistance of the material of a cooking container, which is a to-be-heated object. Therefore, under conditions with relatively-lower heating efficiencies, greater heat losses are induced, which causes components such as induction heating coils to generate greater amounts of heat. Therefore, in order to perform stabilized heating cooking, it is important to provide a cooling structure for cooling the induction heating coils.
Conventionally, as structures for cooling induction heating coils in induction heating cookers of this type, there has been one disclosed in Unexamined Japanese Patent Publication No. 2005-302406 (Patent Literature 2), for example. FIG. 16 is a side cross-sectional view illustrating a conventional induction heating cooker disclosed in Patent Literature 2. As illustrated in FIG. 16, the induction heating cooker disclosed in Patent Literature 2 is provided with a coil unit 100 for induction heating, just under a top plate 50 for placing a to-be-heated object thereon. The coil unit 100 is constituted by an induction heating coil 200, ferrites 300 on which the induction heating coil 200 is placed, a heat dissipation plate 400 in contact with the ferrites 300, and a coil base 500 holding the ferrites 300 and the heat dissipation plate 400.
In the conventional induction heating cooker illustrated in FIG. 16, the plural ferrites 300 are radially placed and held by the coil base 500, and the induction heating coil 200 is placed on the ferrites 300 in contact with each other. The heat dissipation plate 400 is provided with plural holes 400a and 400b for passing cooling air X therethrough, and the cooling air X comes into contact with the heat dissipation plate 400 to cool the heat dissipation plate 400 and, also, comes into direct contact with the induction heating coil 200 to cool the induction heating coil 200. With such a conventional induction heating cooker having the aforementioned structure, the heating coil 200 is cooled by being brought into direct contact with the cooling air X and, also, heat generated from the induction heating coil 200 is partially transmitted to the heat dissipation plate 400 through the ferrites 300 and, thus, the heat is dissipated from the heat dissipation plate 400.
Patent Literature 1: European Patent Application Publication No. 1122983
Patent Literature 2: Unexamined Japanese Patent Publication No. 2005-302406